<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        body{
            height: 3000px;
        }

        div{
            margin: 10px;
            padding: 10px;
            border: 1px black solid;
        }
        .Blo{
            margin: 10px;
            padding: 10px;
            border: 1px black solid;
            width: 1023px;
            height: 334px;
            background-color: #d2d9af;
            background-image: linear-gradient(0deg, #d2d9af 0%, #97D9E1 50%, #ffffff 100%);
        }
        #father{
            position: relative;
        }
        #first{
            background-image: url("../resource/image/1.jpg");
            background-repeat: no-repeat;
            width: 250px;
            height: 250px;
            float: left;
            background-size: cover;
            position: relative;
            position: relative;
            top:20px;
            left:-30px;
        }
        #second{
            background-image: url("../resource/image/2.jpg");
            background-repeat: no-repeat;
            width: 250px;
            height: 250px;
            float: left;
            background-size: cover;
            position: absolute;
            right: 30px;
        }
        #third{
            background-image: url("../resource/image/3.jpg");
            background-repeat: no-repeat;
            width: 250px;
            height: 250px;
            float: left;
            background-size: cover;
        }
        #father:after{
            content: "";
            display: block;
            clear: both;
        }
        div:nth-of-type(4){
            width: 50px;
            height: 50px;
            background: aqua;
            position: fixed;
            bottom: 3px;
            right: 3px;
        }
    </style>
</head>
<body>

</body>
<div id="father">
    <div id="first"></div>
    <div id="second"></div>
    <div id="third"></div>
    <div id="forth"></div>
</div>
<div class="Blo">

</div>
<div class="Blo">

</div>
</html>